The Rotary Dial Telephone
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The first phones had no dial. With switchboards staffed by operators, dials were not needed. But automated systems required something like a dial to enable numbers to be sent to the exchange. The first practical rotary dial was invented in 1898 (US patent No. 597,062). This was by the prolific Alexander Keith and the Erickson brothers. Some credit Almon Strowger (US patent 486,909) with the first dial. However, his version needed 5 wires from the telephone to the central office so was not practical and little used compared to Keith's dial.
Over the next ~25 years the dial continued to be improved with the "numbers plus letters" dial introduced in New York City in 1922. See Note below. See too the section on telephone annunciators.
Dialing causes the line current to be interrupted (e.g., 5 pulses for the digit 5). These pulses are then counted by exchange relays or other recording methods. With a dial, no operator was needed for local calls.
Rotary dial, circa 1900. This dial was circular like the fully mature dial but instead of holes, it had lugs on a finger plate for the user to grab and rotate.
This model is from the Science Museum of London, UK.
The “Candlestick” phone, featuring a dial with numbers and letters, was introduced in the early 1920s
From 1930 to about 1940 the
type-D handset was popular.
100’s of millions of dial phones were made.
Touch Tone dials (keypad) began replacing the pulse dial in 1963.
Source: Paul-F
The world's most beautiful telephone
The Skelton Telephone 1892
Most beautiful? Well, beauty is in the eye of the beholder but this model get high marks from collectors. There are several replicas available because of its eye catching looks and originals may sell for over $3,000 in auction. Of course, this model had no dial because it had not yet been invented so it is not a rotary telephone per the title of this section. ​
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The Swedish inventor and entrepreneur Lars Magnus Ericsson (LM Ericsson Company) personally designed the first model of the skeleton-like telephone. It is a desk type in the form of a naked steel construction, with two black-lacquered inductor magnets, ingeniously curved and twisted into a stand.
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The image above is the model AC110 (375) from circa 1892. The microphone was fitted in an elegantly angled arm that could be pivoted 360 degrees. The hand crank turned a magneto to generate an AC voltage used to trip a switchboard "drop" to inform an operator that a caller was active. It could also call another telephone attached to the same line.
In Sweden this model is called "Tax" (Dachshund), in Australia/UK the Skeleton and in USA the Eiffel Tower. A British Ericsson catalogue describes it as, “This exclusive instrument is a masterpiece of unique design and is undoubtedly the handsomest set in the industry.”
The first model (below) was improved in 1892 when it was equipped with a horizontal telephone handset on a hook (AC110). Although the handset was not a Swedish invention, this Ericsson model set the standard for all 20th-century variants of desk telephones with horizontal headsets. (Some text from [History]). An original AC100 sold at auction for ~$24,000 in 2021. ​
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LM Ericsson's first model from 1884. Image from [Ericsson] and is model AC100 (also 370).
Here are two close ups of this magnificent telephone from auction catalogs.
In 1976, a highly detailed and faithful replica of the iconic model was created by LM Ericsson Company. Only 1,500 pieces were made and initially sold for $3,500 each. It can be found at auctions.
Since Alexander Graham Bell's time, thousands of telephone varieties have emerged. Some are pedestrian designs while others are exotic. Since about 2014, AI generated art has been available. Imagine if Leonardo Da Vinci created a dial telephone, how might it look?
Here are few examples of phone designs created by the DALL-E 2 generative art service. There are many sites devoted to vintage telephones. The coverage here is the very tip of the iceberg. See the excellent Telephone Collectors International (TCI) site; www.telephonecollectors.org for a wealth of resources. Read here how Alexander Graham Bell invented his telephone by accident.
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Notes:
For a deeper dive, see "Early Work on Dial Telephone Systems" by R.B. Hill, Bell Laboratories Record, Jan 1953, page 22.
Also, see the article Bell's first transmitter and the important work of Francis Blake in the same article and the article on Who Invented the Telephone.
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